A Study on Properties of Light Weight Cinder Aggregate Concrete with Silica Fume and Fly Ash as Admixtures Dandu Chinna Narasimhudu Post Graduate Student, Department of Civil Engineering, Annamacharya Institute of Technology and Sciences, Kadapa. Abstract: Porous lightweight aggregate of low specific gravity is used in this lightweight concrete instead of ordinary concrete. The lightweight aggregate can be natural aggregate such as pumice, scoria and all of those of volcanic origin and the artificial aggregate such as expanded blast-furnace slag, vermiculite and clinker aggregate. The main characteristic of this lightweight aggregate is its high porosity which results in a low specific gravity. Dr. P. Sri Chandana, Ph.D HoD, Department of Civil Engineering, Annamacharya institute of Technology and Sciences, Kadapa. 1.2 TYPES OF LIGHT WEIGHT CONCRETE Lightweight solid can be arranged either by infusing air in its organization or it can be accomplished by precluding the better sizes of the total or notwithstanding supplanting them by an empty, cell or permeable total. Especially, lightweight solid can be classified into three gatherings: No-fines concrete Lightweight total cement Aerated/Foamed cement In the present investigations of light weight concrete withcinder aggregate used as light weight aggregate and silica fume and fly ash as admixtures were used.the light weight concrete designed as M20 grade to get structural light weight concrete using cinder aggregate. Compressive strength are studied with replacement of cement in different percentages using silica fume and fly ash 1. INTRODUCTION 1.1 LIGHT WEIGHT CONCRETE Lightweight concrete can be defined as a type of concrete which includes an expanding agent in that it expands the volume of the blend while giving extra qualities, for example, nailbility and diminished the dead weight. It is lighter than the customary cement. The principle fortes of lightweight solid are its low thickness and warm conductivity. Its preferences are that there is a lessening of dead load, speedier building rates in development and lower haulage and taking care of expenses. Fig 1 Cinder Aggregate Fig 2:20 mm Cinder Page 1097
Table 1: Advantages and Disadvantages of Lightweight concrete 2.2CEMENT In India are manufactured the three grades of OPC, namely 33grade, 43 grade and 53 grade. As per the standard testing procedure compressive strength of cement will be obtained after 28days. Apart from OPC, there are several other types of cement, e.g. sulphates resistant cement, colored cement, oil well cement, expansive cement, etc. Ordinary Portland cement of 53 grade Ultra tech cement brand confirming to IS 12269:1987 standard is used in the present investigation. The cement is tested for its various properties as per IS 4031:1988 and found to be conforming to the requirements as per IS 12269:1987. Various tests conducted on cement to determine its properties. Specific gravity of cement Normal consistency of cement Initial and final setting times of cement Compressive strength of cement 1.3OBJECTIVE OF THE PRESENT STUDY In the present investigations of light weight concrete withcinder aggregate used as light weight aggregate and silica fume and fly ash as admixtures were used.the light weight concrete designed as M20 grade to get structural light weight concrete using cinder aggregate. Compressive strength are studied with replacement of cement in different percentages using silica fume and fly ash. 2. MATERIALS USED AND THEIR PROPERTIES 2.1 GENERAL In this chapter deals with the constituents used in preparing the Light weight concrete mixtures. The materials include Ordinary Portland cement (OPC), silica fume, fly ash, coarse aggregate fine aggregate, cinder aggregate and water. Details and testing results of each constituent are given below. 2.3 POZZOLANIC ADMIXTURES IN CONCRETE Pozzolanas are either normally happening or accessible as waste materials. They for the most part contain silica, which gets to be receptive in the vicinity of free lime accessible in concrete when pozzolanic admixtures are blended with bond. The reactivity fluctuates relying on the kind of pozzolana, its compound arrangement and its fineness. In creating nations like India, pozzolanic materials are chiefly accessible as modern waste by-items, Fly cinder, silica smoke, impact heater slag, stone dusted., are a percentage of the mechanical squanders and MetaCem is a quality controlled responsive pozzolana, produced using cleansed kaolin which have pozzolanic receptive properties. 2.4SILICA FUME In the refractories world thirty-five prior, nobody was working with silica smoke and few realized what it was. Inside of a couple of years, it was being utilized as an admixture to block. At the point when amountof Page 1098
substantial Alumina block, mullite was framed in the framework of the block on terminating, giving the block great volume quality, quality and synthetic resistance. 2.5 FLY ASH Fly ash, is also known as fuel-ash, is one of the residues generated in combustion, and comprises the fine particles that rise with the flue gases. In an industrial context, fly ash usually refers to ash produced during combustion of coal. 2.6COURSE AGGREGATE Conventional Natural Aggregate (Granite) and Light Weight Aggregate (Cinder) are used in the concrete mixes. Machine Crushed granite aggregate conforming to IS 383:1970 consisting 20 mm maximum size of aggregates has been obtained from the local quarry. The Cinder is hand broken to 20 mm size. Both granite and cinder have been tested for Physical and Mechanical Properties such as Specific gravity, Bulk Density, Sieve Analysis. 2.7 FINE AGGREGATE Fine aggregate is a mass of finely crushed rock. It is either crushed naturally as seen on the sea shore, in river beds or in deserts. Or it is artificially produced in crusher plants near rock. Sand is classified according to the shape of its particles, which differs depending on where the sand came from originally it is also graded according to the size of its grains. 2.8WATER Water initiates the chemical reaction that produces the binding qualities of cement. Without it,cement is unusable powder and concrete is impossible to make so water is an important ingredient of concrete as it involved to take part in chemical reaction with cement since standard of water influence the strength. It is needed in order to achieve a particular result for to go into the purity and quality of water. 3. EXPERIMENTAL INVESTIGATION 3.1 GENERAL The mix design has been conducted for M20 concrete making use of ISI method of mix design using normal constituents of concrete. In the course of investigation normal granite aggregate has been replaced by light weight aggregate namely (cinder) in percentages of 0%, 25%, 40%, 60%, 75% and 100%. In the present investigation the OPC cement has been replaced by admixture (silica fume) in three percentages i.e. 5, 10, 15 and admixture (fly ash) in three percentages i.e. 10, 20, 30. For the study of various properties, totally 180 specimens have been cast and tested. Here a constant water cement ratio of 0.50 has been adopted The experimental part of the investigation has been planned in the following three stages. Stage 1: Procurement of materials and its testing. Stage 2:Molding of specimens and curing. Stage 3: Testing of specimens. 3.2Details of Specimen Cast A. Compressive Strength of Concrete For each variable three cube specimens were cast. In all 30 cubes of size 150 mm x 150 mm x 150 mm were cast. B. Split Tensile Strength of Concrete For each variable two cylinder specimens were cast. In all 30 cylinders of size 150 mm diameter and 300 mm height, were cast. 3.3 Curing procedure After the casting of cubes and cylinders, the moulds were kept for air curing for one day and the specimens were removed from the moulds after 24 hours of casting. Marking was done on the specimens to identify the specimens. All the specimens were cured in curing tanks for the desired age i.e. 28 days. The identification of the specimens is as follows. Page 1099
Compressive Strength = load/area in N/mm2 Table 2:mix proportions FIG3:Curing of specimens 4.3 Testing of cylinders for split tensile strength This test was conducted in a 200 tones capacity of compression testing machine by placing the cylindrical specimen of the concrete horizontal, so that its axis is horizontal between the plates of the testing of specimens. Narrow strips of the packing material i.e., ply wood was placed between the plates and the cylinder, to receive the compressive stress. The load was applied uniformly at a constant rate. Load at which the specimens failed was recorded and the splitting tensile stress was obtained using the formula based on IS 5816:1970 F1 = 2P/πDL Where p = Compressive load on cylinder L = Length of cylinder D = Diameter of the cylinder 4. TESTING PROCEDURE 4.1 Test for measuring workability For checking the consistency of workability standard tests like slump and compaction factor were conducted and with the addition of super plasticizer workability is maintained more or less constant. 4.2 Testing of cube for compressive strength Compression test was done conforming to IS 516:1959. All the concrete specimens were tested in a 200 tones capacity of compression testing machine. Concrete cubes of sizes 150mm x 150mm x 150 mm were tested for crushing strength, crushing strength of concrete was determined by applying load at the rate of 140 kg/sq.cm/minute till the specimens failed. The maximum load applied to the specimens was recorded dividing the failure load by the area of specimens ultimate compressive strength was calculated. The results are tabulated and graphs are plotted which are presented in the next chapter. Fig4Testing of cube Fig5 Testing of cylinder by split tensile Page 1100
5. DISCUSSION OF TEST RESULTS 5.1 Compressive strength of concrete with replacement of cinder aggregate and silica fume The compressive strength results with 100% natural aggregate being replaced by 0 % cinder aggregate and with different percentages replacements of cement by silica fume are shown in table 7. Thegraphical variations of compressive strength versus percentage replacement of cement by silica fume are shown in fig 5.1. From the above table 7 and fig 5.1 it may be observed that there is an increase in compressive strength for the replacement of cement by silica fume as 5% and for 10% and 15% the strength gets decreased. The compressive strength results with 25% natural aggregate being replaced by 75% cinder aggregate and with different percentage replacements of cement by silica fume are shown in table 7. The variations of compressive strength versus percentage replacement of cement by silica fume are shown in fig 5.1. From the above table 7 and fig 5.1 it may be observed that there is an increase in compressive strength for replacement of cement by silica fume up to 5% and for 10% and 15 % the strength gets decreased. Fig 6Compressive strength with different percentages of cinder aggregate with different percentages of silica fume 5.2 Compressive strength of concrete with replacement of cinder aggregate and fly ash The compressive strength results with 100% natural aggregate being replaced by 0 % cinder aggregate and with different percentages replacements of cement by fly ash are shown in table 8. The graphical variations of compressive strength versus percentage replacement of cement by fly ash are shown in fig 5.2. From the above table 8 and fig 5.2 it may be observed that there is an increase in compressive strength for the replacement of cement by fly ash as 20% and from 10% and 30% the strength gets decreased. Fig 7 Compressive strength with different percentages of cinder aggregate with different percentages of fly ash 5.3 Split tensile strength of concrete with replacement of cinder aggregate and silica fume The split tensile strength results with 100% natural aggregate and with different percentages replacements of cement by silica fume are shown in table 9. The variation of split tensile strength versus percentage replacement of cement by silica fume are shown in fig 5.3. From the above table 9 and fig 5.3 it may be observed that there is an increase in split tensile strength for the replacement of cement by silica fume as 5% and from 10% and 15% the strength gets decreased. Page 1101
The split tensile strength results with 25% natural aggregate being replaced by 75% cinder aggregate and with different percentage replacements of cement by silica fume are shown in table 9. The variations of split tensile strength versus percentage replacement of cement by silica fume are shown in fig 5.3. From the above table 9 and fig 5.3 it may be observed that there is an increase in split tensile strength for replacement of cement by silica fume as 5% and from 10% and 15% the strength gets decreased. variations of split tensile strength versus percentage replacement of cement by fly ash are shown in fig 5.4. From the above table 10 and fig 5.4 it may be observed that there is an increase in split tensile strength for replacement of cement by fly ash as 20% and from 10% and 30% the strength gets decreased. Fig 9 Split Tensile strength with different percentages of cinder aggregate with different percentages of fly ash Table 3: Tests Results on Cement Fig 8 Split Tensile strength with different percentages of cinder aggregate with different percentages of fly ash 5.4 Split tensile strength of concrete with replacement of cinder aggregate and fly ash The split tensile strength results with 100% natural aggregate and with different percentages replacements of cement by fly ash are shown in table 10. The variation of split tensile strength versus percentage replacement of cement by fly ash are shown in fig 5.4. From the above table 10 and fig 5.4 it may be observed that there is an increase in split tensile strength for the replacement of cement by fly ash as 20% and from 10% and 30% the strength gets decreased. Table 4: Sieve Analysis of Fine Aggregate The split tensile strength results with 25% natural aggregate being replaced by 75% cinder aggregate and with different percentage replacements of cement by silica fume and fly ash are shown in table 10. The Page 1102
Table 5: Sieve Analysis of Coarse Aggregate Table 7: Compressive strength of concrete with replacement of cinder aggregate and fly ash Table 6: Compressive strength of concrete with replacement of cinder aggregate and silica fume Fig 10: Failure of cylinder 6. CONCLUSIONS 1. From the study it is concluded that 5 % silica fume is giving the best results when compare to 10% and 15% silica fume and also from fly ash 20% is giving best results when compare to 10% and 30%. 2. From the study it may concluded that the usage of light weight cinder aggregate to some extent (60%) Page 1103
and granite aggregate (40%) using admixture as silica fume and fly ash has proved to be quite satisfactory strength when compare to various strengths studied. 3.It can be conclude that due to porous nature Cinder aggregate's quality is low in comparison with normal aggregate 4. The results indicate that the compressive strength is decreases with the increase in percentage of cinder. 5. The results indicate that the split tensile strength is decreases with increase in percentage of cinder. 6.Compressive strength of 5% silica fume concrete is more than the 10% and 15% silica fume concrete at 28 days Similarly tensile strength of 5% silica fume is greater than the 10% and 15% silica fume concrete at 28 days. 7.Compressive strength of 10% fly ash concrete is more than the 20% and 30% fly ash concrete at 28 days Similarly tensile strength of 10% fly ash concrete is greater than the 20% and 30% fly ash concrete at 28 days. 7. REFERENCES 1.ASTM International C-33 (2003), "Standard Specifications For Concrete Aggregate", American Society For Testing And Materails", United States, Annual Book Of ASTM Standards, Vol. 04. 02. PP. 1-11. 4.CananTasdemir, Mehmet A. Tasdemir, Nicholas Mills end et al., (1999), "Combined Effect Of Silica Fume, Aggregate Type, and Size On Post Pear Response Of Concrete In Building", ACI Material Journal, Vol. 96. No.1, PP. 74-83. 5.G. Barton, Russell A. Cook, et al., (1991), "Standard Practice For Section Proportions For Structural Light Weight Concrete (ACI 221.2)", ACI Material Journal, Vol. 87, No.4, PP. 638-651. 6.G. AppaRao. (2001), "Development Of Strength With Age Of Mortar Containing Silica Fume", Cement And Concrete Research, vol.31, PP. 1141-1146. 7.Hang Zhang and Odd E Gjorv, (1991), "Characteristics of Light Weight Aggregate for High-strength Concrete", ACI Material Journal, Vol.88, No.2, PP. 150-158. Author Details Dandu Chinna Narasimhudu Post Graduate Student, Department of Civil Engineering, Annamacharya Institute of Technology and Sciences, Kadapa. 2.ASTM International C-330, (2005), "Standard Specifications For Light weight Aggregates For Structural Concrete", American Society For Testing and Materials, United States, Annual Book of ASTM Standards, Vol.05. PP. 1-4. 3.Clarke, J.L., Structural Light Weight aggregate Concrete. Blackie Academic and professional 1993, 29 Page 1104